1. Field of the Invention
The present invention relates to an ink jet recording apparatus to be applied to image processing apparatuses such as a copying machine, a printer, and a facsimile, and a recovering method for the ink jet recording apparatus.
2. Related Background Art
There are conventionally available recording apparatuses for recording images on recording media in various recording modes, for example, a wire dot mode, a temperature-sensing mode, a heat transfer mode and an ink jet mode. Among these recording apparatuses, an ink jet recording apparatus records an image on a recording medium by discharging fine ink droplets from fine discharge ports of an ink jet recording head, and generally has a head recovering unit including wiping means for removing contaminant from a surface of the ink jet recording head on which nozzles are arranged and sucking means for exhausting ink and bubbles from the nozzles.
The ink jet recording apparatus is generally of a serial type recording apparatus which reciprocally scans an ink jet recording head in a direction intersecting or perpendicular to a conveying direction of a recording sheet.
An example of such a conventional serial type ink jet recording apparatus is shown in FIG. 14. This ink jet recording apparatus has a recording head 102, recording head conveying means, recording medium conveying means and a head recovering unit 101.
Though the recording head 102 is not described in detail, this head is a unit which is used for recording data by discharging ink from nozzles to a recording medium (not shown) utilizing heat energy produced by driven electrothermal converting elements and mechanical oscillating energy of piezo elements, and mounts ink tanks 103 and 104. This recording head 102 is mounted on a carriage 105. The carriage 105 is reciprocally movable in a width direction of the recording medium by an operation of the recording head conveying means. The recording medium (for example, recording sheet) on which data is to be recorded by the ink jet recording apparatus is set in a sheet feeding tray 109, fed by a sheet feeding roller 110 to a recording portion for recording, and further conveyed by a conveying roller 107 and pinch rollers 108. The recording medium conveying means is a mechanism which includes the conveying roller 107 and the pinch rollers 108.
A head recovering unit 101 is disposed outside a recording range of the recording head 102. This head recovering unit 101 includes wiping means for removing contaminant from a surface of the recording head on which nozzles are disposed, sucking means for exhausting ink, bubbles and the like out of the nozzles of the recording head. In this ink jet recording apparatus, ink is discharged from the recording head 102 while scanning with the carriage 105 in a condition where the recording medium is conveyed to the recording portion and the recording medium is conveyed at a predetermined pitch each time a cycle of scanning is completed. The scanning with the carriage 105, the discharge of ink from the recording head 102 and the conveyance of the recording medium at the predetermined pitch are carried out alternately to record data on the recording medium.
Such a conventional ink jet recording apparatus requires independent driving mechanisms for the recording head conveying means which moves the carriage 105, the recording medium conveying means which moves the recording medium and the recording head recovering unit 101 which operates the sucking means and the like respectively, thereby having exclusive driving sources such as motors. Furthermore, a driving mechanism for feeding the recording medium to the recording portion may be separate from a driving mechanism for conveying the recording medium in the recording portion and a sheet discharge portion downstream the recording portion, and these driving mechanisms may have driving sources respectively. Furthermore, cap means for close sealing a nozzle surface of the recording head 102 and the sucking means may be driven by independent driving mechanisms and driving sources respectively which are separate from each other. Since a conventional ordinary ink jet recording apparatus has independent driving mechanisms for various use and includes a large number of driving sources as described above, the apparatus is large as a whole and requires a high manufacturing cost.
In order to reduce a manufacturing cost, a certain ink jet recording apparatus utilizes a force for driving recording medium conveying means as a driving force of a recovering operation. This apparatus connects a driving source of the recording medium conveying means to a driven portion (for example, sucking means) of a head revering unit through a drive switching clutch at a timing for a recovering operation. This drive switching clutch is configured to operate in conjunction with a movement of a carriage mounting a recording head and connect the driving source of the recording medium conveying means to the head recovering unit, for example, when the carriage reaches a home position outside a recording range. However, this configuration imposes a heavy lead on the carriage during the movement and forces the carriage to have rather a surplus moving distance for operating the clutch, thereby resulting in enlargement of a width of the apparatus as a whole.
Furthermore, there is an ink jet recording apparatus of the so-called full line type which uses a fixed long linear head having a nozzle row substantially equal or longer to or than a width of a recording medium and does not require a carriage or a carriage moving mechanism. This full line type ink jet recording apparatus does not use recording head conveying means, but has recording medium conveying means for moving a recording medium and a recording head recovering unit for operating a sucking mechanism and the like, which have independent driving mechanisms respectively and requires driving sources for these mechanisms respectively. This full line type ink jet recording apparatus does not move a recording head and cannot adopt the above described configuration which switches a drive switching clutch in conjunction with a movement of a carriage.
An object of the present invention is to provide an ink jet recording apparatus which is applicable as both the serial type and the full line type, reduce a required number of driving sources, permits saving a space and has a high reliability as well as a recovering method for the apparatus.
Another object of the present invention is to provide an ink jet recording apparatus comprising a head recovering unit for recovering a discharge function of an ink jet recording head, a cap member disposed on the head recovering unit to tightly close ink discharge ports, a recording medium conveying mechanism for conveying a recording medium, and a connecting unit for switching transmission and non-transmission of a driving force to the head recovering unit in conjunction with a capping operation of the cap member.